Sensor module for sensing forces to the head of an individual and wirelessly transmitting signals corresponding thereto for analysis, tracking and/or reporting the sensed forces

ABSTRACT

Sensor module for sensing forces to the head of an individual and wirelessly transmitting signals corresponding thereto for analysis, tracking and/or reporting the sensed forces.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation in part of U.S. application Ser. No.15/285,251 filed Oct. 4, 2016, entitled “SENSOR MODULE FOR SENSINGFORCES TO THE HEAD OF AN INDIVIDUAL AND WIRELESSLY TRANSMITTING SIGNALSCORRESPONDING THERETO FOR ANALYSIS, TRACKING AND/OR REPORTING THE SENSEDFORCES” which is a continuation of and claims priority under §120 toU.S. patent application Ser. No. 14/464,074, entitled “SENSOR MODULE FORSENSING FORCES TO THE HEAD OF AN INDIVIDUAL AND WIRELESSLY TRANSMITTINGSIGNALS CORRESPONDING THERETO FOR ANALYSIS, TRACKING AND/OR REPORTINGTHE SENSED FORCES,” filed Aug. 20, 2014. U.S. patent application Ser.No. 14/464,074, entitled “SENSOR MODULE FOR SENSING FORCES TO THE HEADOF AN INDIVIDUAL AND WIRELESSLY TRANSMITTING SIGNALS CORRESPONDINGTHERETO FOR ANALYSIS, TRACKING AND/OR REPORTING THE SENSED FORCES,”filed Aug. 20, 2014, is a non-provisional of and claims priority under35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No.61/881,275, entitled “SENSOR MODULE FOR SENSING FORCES TO THE HEAD OF ANINDIVIDUAL AND WIRELESSLY TRANSMITTING SIGNALS CORRESPONDING THERETO FORANALYSIS, TRACKING AND/OR REPORTING THE SENSED FORCES,” filed Sep. 23,2013; and U.S. Provisional Patent Application Ser. No. 61/868,004,entitled “SENSOR MODULE FOR SENSING FORCES TO THE HEAD OF AN INDIVIDUALAND WIRELESSLY TRANSMITTING SIGNALS CORRESPONDING THERETO FOR ANALYSIS,TRACKING AND/OR REPORTING THE SENSED FORCES,” filed Aug. 20, 2013, allof which applications are herein incorporated by reference in theirentirety. This application also is a non-provisional of and claimspriority under 35 U.S.C. §119(e) to U.S. Provisional Patent ApplicationSer. No. 62/274,575 entitled “SENSOR MODULE AND METHOD FOR SENSINGFORCES APPLIED TO THE BODY,” filed Jan. 4, 2016, of which application isincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to the sensing of forces to the head of anindividual and, more particularly, to the use of a high-quality, mobilephysiometric sensor module with a multi-layer distributed data storage,analysis and presentation structure.

Brief Discussion of the Related Art

Individuals engaged in a wide variety of physically demanding sports andactivities risk brain or other serious injuries resulting from impact,hyper-extension and other extreme movements or events. Some examples ofrisk-laden sports include, among many others, football, soccer,baseball, basketball and rugby.

Most attempts to reduce the effects of impacts have included sensorsmounted in helmets, in the mouth, or along the side of the head. They donot provide real-time information relating to occurrence of impactevents to permit an individual being monitored to be removed from activeplay for the individual's safety.

SUMMARY OF THE INVENTION

According to some aspects of the present invention, a sensor is providedthat the senses forces applied to the head of an individual whereindications of the sensed forces can be transmitted to one or moreremote locations permitting visualizations of the force events to whichan individual is exposed.

Aspects of the present invention provide accurate sensing of forceevents and allows data analysis to be performed in real-time and,through more extensive post processing, to permit the warning ofplayers, coaches, parents and others of events which are potentiallyharmful and could require medical attention. Other aspects of thepresent invention serve to protect participants involved in sportingevents or other activities, including players, coaches, managers andparents, for example, by informing them in real-time of impacts to anindividual, assisting them in determining if or when the individualshould be removed from the activity for the individual's safety.

Some advantages of different aspects of the present invention include,without limitation, increasing athletic performance while decreasingrisk, isolating players who have taken severe or repeated impacts to thehead, reinforcement of proper techniques, providing coaches, trainersand parents confidence that they are making a game or activity safer.The sensing device or module, sometimes referred to as a SIM sensor, iscarried on or in a support having a shape to surround the head, such asa headband or skull cap, not requiring a helmet or other specialequipment, to transmit impacts to the head in real-time. Someapplications of the present invention displays data in real-time forathletes on a team as well as for individual use, and stores datahistorically for each individual being monitored such that the data canbe accessed for any time before or after an event for analysis bycoaches, trainers, doctors, athletic directors and parents or the like.A software application that can be used to implement aspects of thepresent invention can allow for functions performed by aspects of thepresent invention to be activated for the duration of a contact drill inpractice such that any subsequent impact that occurs while the system isactivated can be saved for later analysis relating to specific drills.Once a particular drill has been completed, head impacts that occurredduring the drills can be isolated such that athletes recording thehighest G-force impacts can be determined allowing a coach or othersinvolved in the drill to apply special coaching to decrease the amountof impact to a particular athlete's head.

One aspect of the present invention is the positioning of the impactsensor module in alignment with the median nuchal line of the occipitalbone of the skull thereby providing extremely accurate data. Positioningof the sensor can be accomplished by placing the sensor module in apocket formed in a support having a shape to surround the head, suchthat the sensor module can be comfortably worn during activities at aposition to record all impacts and accelerations greater than apreprogrammed set-point. The support can be formed of a headband, askull cap, or fabric tied around the head like a bandana, and the pocketcan be open to facilitate insertion of a sensor module or closed to formthe sensor module integrally with the support.

In another aspect, one embodiment of the present invention allows theperformance of cognitive and balance evaluation tests to gauge anindividual's performance immediately after a possible concussive eventin real-time. Balance evaluation tests can be accomplished with thesensor module in place by proper programming of the sensor module or byother equipment coordinating with the sensor module.

Another aspect of the present invention includes a method for monitoringimpact forces to the head utilizing a sensor module at the back of thehead in alignment with the median nuchal line of the occipital boneutilizing local data service infrastructure and/or global data surfaceinfrastructure.

In a further aspect, the present invention permits monitoring of impactforces to the head of individuals participating in a team activity wherea sensor module is worn by each of the participants and a datacollection wireless access point receives signals from the sensormodules.

According to one aspect, a sensor is provided comprising a flexiblehousing comprising a plurality of 3-axis accelerometers, the flexiblehousing being adapted to be worn by a user and being in contact with abody part of the user, and a module coupled to the accelerometersincluding a processor which is adapted to sense forces experienced bythe body part. In one embodiment, the sensor is constructed within aheadband. In another embodiment, the flexible housing comprises at leastthree 3-axis accelerometers, and wherein the housing comprises flexiblecouplings between the at least three 3-axis accelerometers.

According to another embodiment, the sensor further comprises flexiblecircuits that couple the module to two of the at least three 3-axisaccelerometers. In yet another embodiment, at least one of the 3-axisaccelerometers is positioned at the back of the head of the user inalignment with the median nuchal line.

In another embodiment, the module is adapted to determine rotationalacceleration from multiple measurements of linear acceleration. Inanother embodiment, the module is adapted to receive at least threemeasurements of linear acceleration from non-colinear points within thesensor.

In another embodiment, the sensor further comprises a sensor adapted tomeasure rotational velocity. In another embodiment, the sensor isadapted to measure rotational velocity includes a MEMS gyro. In oneembodiment, the module is adapted to power on the MEMS gyro responsiveto a detection of an event. In another embodiment, the event includes ameasurement of an acceleration above a predefined threshold.

In another embodiment, the sensor further comprises a proximity sensoradapted to detect whether the sensor is in contact with the body part ofthe user. In one embodiment, the module is adapted to power on thesensor responsive to detection by the proximity sensor indicates thatsensor is being worn by the user. According to another embodiment, theproximity sensor includes a capacitive sensor pad.

In another embodiment, the housing includes a plurality of rigidcircuits associated with each of the plurality of 3-axis accelerometers.In yet another embodiment, the plurality of rigid circuits are coupledby a plurality of flexible circuits. In another embodiment, the sensorfurther comprises, within the flexible housing, at least one antennaadapted to communicate with one or more external systems. In anotherembodiment, the sensor comprises, within the flexible housing, acapacitive sensor pad adapted to detect proximity of the sensor to thebody part of the user. In yet another embodiment, at least one of theplurality of 3-axis accelerometers is coupled to a rigid circuitassociated with the module, the at least one accelerometer being coupledto the rigid circuit by a flexible circuit.

Other aspects and advantages of the present invention will beappreciated from the following description of the invention taken inconjunction with the drawings. The drawings and the followingdescription are meant to be exemplary only of an embodiment of thepresent invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective showing of a skull relative to a sensor moduleaccording to one embodiment of the present invention showing thepositioning of the sensor module in substantial alignment with themedian nuchal line of the occipital bone of the skull.

FIG. 2 is a plan view of a sensor module according to one embodiment ofthe present invention with an extended antenna.

FIG. 3 is a perspective view of a headband with the sensor module ofFIG. 2 held in a pocket therein.

FIG. 4 is a perspective view of a skull cap on a head and holding thesensor module shown in FIG. 2.

FIG. 5 is a block diagram of a system according to one embodiment of thepresent invention utilizing a plurality of sensor modules.

FIG. 6 is a diagrammatic representation of the system of one embodimentof the present invention utilized with an athletic field.

FIG. 7 is a plan view of a display of a PDA, such as a smartphone,displaying data obtained with one embodiment of the present inventionfor an individual.

FIG. 8 is a plan view of a computer display of data obtained with oneembodiment of a system consistent with principles of the presentinvention for a plurality of individuals.

FIG. 9 is a rear view of a headband carrying a sensor module accordingto one embodiment of the present invention positioned on the rear of theskull of an individual.

FIG. 10 shows a side view of a sensor and headband arrangement accordingto one embodiment.

FIG. 11 shows a top view of a sensor and headband arrangement accordingto one embodiment.

FIG. 12 shows an accelerometer arrangement according to one embodiment.

FIG. 13 shows a side view of a sensor and headband arrangement accordingto one embodiment.

FIG. 14 shows a sensor and headband arrangement according to oneembodiment.

DESCRIPTION OF THE INVENTION

As shown in FIG. 1, a sensor module 10 in accordance with certainaspects of the present invention is typically a small, environmentallysealed device incorporating a sub GHz transceiver, a low powermicroprocessor, a 3-axis high g accelerometer, a 3-axis low gaccelerometer, a 3-axis gyroscope, a non-volatile memory, a battery, abattery charger and other support circuitry. The sensor module 10 issometimes referred to herein as a mobile sensor or a SIM or an impactmonitor. The sensor module 10 is in substantial alignment with themedian nuchal line of the occipital bone of the skull shown in dashedlines at N and, normally, between the inferior and superior nuchallines. One embodiment utilizes a curved elongate antenna 12 extendingfrom the sensor module housing toward the left side of the head. Theanatomical axes denoted as X_(a), Y_(a) and Z_(a), the sensor axesdenoted as X_(s), Y_(s) and Z_(s) and the subtended angle θ areillustrated in FIG. 1. The anatomical axes allow correlation with theaxes in the sensor module.

A headband 14 is shown in FIG. 3 and has a pocket 16 arranged along aninner surface or lining and cooperating with an elongated arcuate pocket18 such that the sensor module 10 and antenna 12 shown in FIGS. 1 and 2can be inserted within the pocket 16 and arcuate space 18 such that thesensor module is positioned adjacent the skull. The headband ispreferably made of a non-stretchable material having only a smallsection thereof made of elastic to allow for form fitting. The headbandthus stabilizes the sensor module and prevents “double hit” sensing bykeeping the sensor module firmly in place against the skull. The outersurface of the headband adjacent the pocket 16 can carry indicia I tofacilitate accurate location of the sensor module on the head. Theindicia can also include an arrow to make certain that the headband isproperly oriented.

A skull cap having a structure around the periphery including the pocketstructure described above is shown in FIG. 4.

In one embodiment, the sensor module communicates with an access pointin a wireless fashion such as over the 915 MHz ISM band in the U.S.Other bands are possible through minor firmware and hardware changesover the frequency range of 300 MHz-348 MHz, 389 MHz-464 MHz and 779MHz-928 MHz. The sensor module 10 is capable of measuring linearacceleration events up to +/−400 G and rotational velocities up to+/−2000°/sec at a 1 KHz sample rate. An “event” is defined as a 3-axis Grecording of 10 ms before and 52 ms after a threshold is exceeded. Thethreshold is calculated as (xg²⁺y_(g) ²⁺zg²) and is adjustable. When anevent is detected, the event is transmitted wirelessly in real-time(within a few tenths of a second) to the access point.

If wireless communication with the access point is interrupted, theevent is stored in internal non-volatile memory. When wirelesscommunication is restored, any saved events are transmitted.

As shown in FIG. 5, the system of one embodiment of the presentinvention includes, in an exemplary embodiment, a plurality of sensormodules each in communication with an appropriate access point 20.Multiple impact monitors 10 can be used concurrently with a singleaccess point 20. The access point and its associated impact monitors areassigned primary and secondary communication channels (from a set ofover 30 for the 915 MHz band). If communication is not established onthe primary channel within a few seconds, the impact monitors try on thesecondary channel. This procedure is repeated until communication isestablished. The communication protocol is packet based with robusterror checking/correction to increase the likelihood of valid dataexchange. Each packet includes globally unique source and destinationdevice identifiers to further insure data integrity. Each ‘event’ packetis tagged with a time stamp for unambiguous correlation of the data‘event’ with the physical event producing it.

The local data services infrastructure 22 and the global data servicesinfrastructure 24 all achieve the data integrity goal by holding allmeasurements until they have been successfully and verifiablytransmitted to the next stage in the system.

The system according to one embodiment of the present invention isformed of three main subsystems as shown in FIG. 5.

-   -   1. Mobile sensors 10 (SIMs, sensor modules).    -   2. Local Data Services 22 (LDS) infrastructure:        -   Data collection wireless access point (AP).        -   Local data storage.        -   Local data services (analysis, formatting and presentation).        -   Local administrator and account services.    -   3. Global Data Services 24 (GDS) infrastructure:        -   Cloud-based server facilities, essential for reliability and            scalability.        -   Data storage and perpetual archival and back-up.        -   Data analysis, formatting and presentation.        -   User-account services and revenue management.

In addition, subscribers 26 (local and global) represent the finalconsumers of all available analytics.

The diagram in FIG. 6 shows a typical football field, with the systeminstalled at the sidelines. In this example, there can be one (shown) ormore WAP (WiFi Access Points) 20 to provide adequate WiFi coverage toboth sides of the playing field (staff and spectators). Staff for bothteams have their own display devices (iPAD, etc.), and are grantedaccess to their respective team's information only.

The sensor modules each collect data on impact events to the wearer'shead that occur during typical sports activities (football, soccer,etc.). The sensor data being recorded includes 3-axis linearaccelerometer data, 3-axis rotational data, diagnostics and status, timestamp, and individual device identification as shown in FIG. 7. Thesensor modules (SIMs) also contain a small processor that handles sensordata acquisition and manages a wireless radio link with the AP. The SIMscan incorporate a wider and more extensive range of sensor inputs,including standard health monitoring functions (heart rate, respiration,temperature, GSR, etc.) and other physiological parameters.

Impact-event data from the sensor modules are transmitted to the nearbyaccess point via a low-power 900 MHz radio link. The data is received bythe AP, processed and presented almost instantaneously to nearbycoaches/administrators through the LDS. The LDS infrastructure includesthe AP, plus a local computer (PC). This subsystem primarily serves as areal-time data collection and storage unit.

The LDS can be physically deployed at the sidelines, as a mobile LDS oras a fixed LDS at a given sports complex or playing field/stadium/court.In either case, the functionality of the LDS remains the same:

-   -   The AP function block provides the RF link to communicate with        all SIM devices within the sports arena.    -   The AP streams all SIM data to the LDS unit controller (PC).    -   The LDS controller provides bulk local storage for SIM data.    -   The LDS controller also provides a limited range of analytics,        formatting and presentation services.        -   Without an internet connection (access to the GDS),            analytics would be limited to the data currently stored in            the LDS.        -   Local user-access would be via a local WAP device (WiFi            Access Point). The analytics are accessed and presented            using a common web- GUI interface, using a typical            web-browser on a laptop or tablet (or iPhone, iPad, etc.).        -   Optionally, the user access can be a custom iPhone/Pad            application, rather than using a browser interface. A custom            iOS/Android application can be used.        -   The LDS services are generally meant for use by the nearby            coaches and administrative staff.

The LDS should be connected to the global internet (and thus, the GDS)whenever possible. However, the reality is that many sports venues(football fields, soccer fields, etc.) have little or no access to theglobal internet, and often lack even AC power.

As an option to a direct internet connection, the LDS can utilizecommonly available “LAN/CELL” bridge devices, which allow the use ofpublic cellular networks (GSM, 3G, 4G-LTE, etc.) as the gateway to theinternet (and therefore, the GDS). The LAN/CELL bridge devices aregenerally compatible with a wide range of cellular networks. In mostcases, all that is required is a prepaid cellular card plugged into theLAN/CELL bridge unit.

The physical implementation of the LDS has as basic elements, optionsfor fixed or mobile deployments, AC or solar power, battery power, LANhub, WAP (WiFi-AP), and a cellular-LAN bridge device.

Some of the features of the present invention include

For the Mobile LDS:

-   -   Rugged, weather-proof enclosure, suitable for portable        hand-carried usage    -   Carrying handles.    -   Locking cover(s).    -   PC based, with integral high-reliability storage units        (preferably SSD), able to withstand the rigors of mobile use at        sporting events.    -   Internal battery supply, sized to provide at least 8 hours of        run-time.    -   Battery AC charging port: Accepts AC line-voltage input.    -   Battery DEPENDENT CLAIM charging port: Accepts typical        automotive 12 VDC (nominal) input.    -   Video output port: VGA/HDMI/DVI, for attaching a direct console        display.    -   Antennae port.

For the fixed LDS:

-   -   Rugged, weather-tight enclosure, suitable for outside use.    -   Mounting flanges and fixing hardware suitable for mounting to        walls, poles, ceilings.    -   Locking cover(s) with security or tamper-evident features and        enclosure-access alarm switch.    -   PC based, with integral high-reliability storage units (possibly        SSD).    -   Able to withstand considerable temperature extremes.    -   Internal battery supply, sized to provide at least 2 hours of        run-time.    -   AC input port, for normal operating power.    -   An on-board charger to keep the internal battery charged in case        it's    -   needed.    -   Video output port: VGA/HDMI/DVI, for attaching a direct console        display.    -   Antenna port.

For networking options:

-   -   LAN port so the LDS can connect directly to a 10/100/1G LAN        network.    -   WiFi-node so the LDS can connect to a camput-wide wireless        network as a client.    -   WAP (WiFi AP) so the LDS can provide a local WiFi “network        cloud” and the LDS-generated analytics can be accessed locally        by coaches on their own laptops or other devices.

The Global Data Services (GDS) subsystem can be considered “cloud based”insofar as it exists as a collection of stored sensor data, programs,and the physical computing hardware could be provided by any number ofservice providers in this field.

There are many advantages of implementing a “cloud based” design ratherthan using fixed in-house server hardware implemented using commodityPCs. The key elements of a cloud based strategy can be summarized asfollows:

-   -   Location: Server hardware and related data storage facilities        can be placed nearly anywhere in the world, wherever operating        costs and network accessibility are optimal for the application.    -   Reliability: Cloud servers offer much higher operational        reliability, and often feature auto-failover to on-site (or        remote) backup servers. Failover events are usually transparent        to the hosted applications and any attached users.    -   Data backups: Automatic backups of data and programs. Proper        procedures and facilities management ensures data integrity and        security, for both on-and off-site backup archives.    -   Scalability: As the underlying dataset grows, and the number of        attached users increases, the server architecture will need to        scale u accordingly and do so in a manner that does not require        a major redesign of either the dataset or the related        application programs.        -   At the low end, just a fraction of one server (PC) may be            utilized by employing a virtual OS “slice” of the available            computing power of that one PC.        -   As requirements grow, dedicated servers and even multiple            servers can be utilized to share the attached-user load and            access to huge perpetual datasets.    -   Network access: A large cloud based server will have dedicated        top-tier access to the global internet. This will be necessary        to efficiently handle the expected number of subscribers.    -   Infrastructure: The facilities, power, cooling and security are        all managed and cost-optimized not just for one or a few        servers, but for an entire server-farm encompassing potentially        many thousands of servers.    -   Site Backup: High availability cloud service providers often        provide geographically diverse locations. This enables a rapid        cutover and recovery from catastrophic events (earthquakes,        floods, etc.).

The SIM sensors, AP+LDS, and GDS, together form a system whose primarypurpose is data collection, storage, analysis and presentation.

A key element of the system is the acquisition and perpetual long-termstorage of all available sensor (SIM) data. Over time, no doubt therewill be many ways of analyzing that data for various purposes. Sometimesfor the user's own personal “performance monitoring” needs. At othertimes, the data will be invaluable for analysis of athletic performanceand related injuries, correlating with demographics other recordedfactors.

FIG. 8 shows a user interface which can be used as an exemplary layoutof a sensor-event record, as it would be stored (locally) in the LDS,and transferred to/from the GDS (and stored there as well). Thesensor-event record, as shown, contains discrete fields which are, inmost cases, simply extracted from the raw sensor-event data (asdelivered over the RF link). These discrete fields are brought out sothat the LDS/GDS database engine (mySQL, etc.) can use those fields toefficiently index and organize the records. Whether the data storage (ondisk) is a “relatively small” database like on the LDS, or scaled up to“multi-terabyte” database (on the GDS), it is important to bring outsome fields like this because the database engine is most efficient atwhat it does best-indexing and accessing data organized into fields. Onthe LDS there will be a single SQL (or other) program managing eventrecords. On the GDS, the equivalent “SQL engine” function can easily bescaled up to many servers, all accessing the same storage unit,providing analytics for many thousands of users worldwide. Keeping theevent-record the same everywhere keeps things uniform. The system reliesnot only on the sensor data, but a number of interrelated databaseswhich ensure the proper identification, storage, categorization,analysis and distribution of the results. The sensor event records arestored and managed by the database engine (SQL, etc.), using one or moreof the “-ID” fields as primary index keys. The user database containsdetailed user identification (name, address), and a list of allSIM-ID/IDX's that have been assigned to this user.

Each organization (school, university, club, etc.) will be registeredinto the system, and each organization will be responsible for one ormore AP+LDS units. Each AP+LDS unit will be registered and activatedbefore it can participate in the system. This is mainly to prevent theuse of unauthorized copies of the LDS.

The subscriber database authenticates the final consumers of the sensordata and its derivative analytics. Subscribers are pay-for-access users,and therefore a related mechanism will be the billing and user-accountmanagement for each subscriber. There will be various subscriber accesslevels.

The most common access method, generally compatible with most if not alldevices, is a typical browser-based GUI. It would be accessed by a fixedURL. The browser interface GUI should be straightforward and as simpleas possible in terms of using the “special features” of any particularbrowser. In fact, all analytics should be delivered as graphic images(JPEG/GIF/PNG) that are computed and delivered as needed. Some of thebrowsers to support include:

-   -   IE (Microsoft, version 6+)    -   Safari (Apple)    -   Opera (PC and mobile)    -   Google Chrome    -   Firefox

The browser GUI interface couldimilar to the “large tablet” version ofthe iOS/Android apps, taking full advantage of a much larger screen.Also, browser access usually means that printing of analytics will bepossible.

The following is a general description of data flow activities withinthe LDS:

-   -   1. The LDS Windows-app:        -   a. Receive sensor data from the AP (RF-link).        -   b. Unscramble or otherwise decrypt, then validate, the data.        -   c. Create standardized “sensor event records”.        -   d. Store these records on the local hard-drive using the            resident database engine (mySQL, etc,).        -   e. Act as an admin-console for configurations settings in            the system.        -   f. Generates requested analytics from the local database.        -   g. Cache all requested analytics. These will be used locally            by the web-server and app-server delivery subsystems.        -   h. Upload any new sensor-event records to the GDS.            -   i. Local sensor-event caching should have an                admin-configurable “cache size” setting. Usually it will                be set to “limited to disk space”, but in some cases it                might be “limited to the last 12 months of data”.        -   i. Download sensor-event records from the GDS, for any            analytics-requests which require sensor-event records which            aren't already stored locally.        -   j. Manage user-registration (assignment of SIMs).        -   k. Manage user and subscriber authentication.            -   i. Download account data and credentials from the GDS                whenever possible.            -   ii. It will be necessary to locally cache                user/subscriber credentials, since the LDS will likely                not have a permanent internet connection to the GDS.

One or more of the following software capabilities can be used:

-   -   2. A resident web-server will serve analytics to locally        connected (via LAN or localized WiFi cloud) subscribers that are        accessing the system using a web- browser.    -   3. A resident iOS app-server will serve analytics to locally        connected (via LAN or localized WiFi cloud) subscribers that are        accessing the system using an iOS device.    -   4. A resident Android app-server will serve analytics to locally        connected (via LAN or localized WiFi cloud) subscribers that are        accessing the system using an Android device.    -   5. A resident Windows Phone app-server will serve analytics to        locally connected (via LAN or localized WiFi cloud) subscribers        that are accessing the system using a Windows Phone device.

The following is a general description of programs running on the GDS(via a Cloud Service):

-   -   1. Operating system.    -   2. A database engine.    -   3. LDS host-side server module.    -   4. Web server module.        -   a. Any web server-related plug-ins and support programs            (PHP, Perl, Java, Python, etc.) that may be necessary.        -   b. The custom “website” (HTML and support files), designed            to implement a web-based GUI. This would be designed to look            very similar (but not identical) to the LDS version.    -   5. iOS Application Server module.    -   6. Android Application Server module.    -   7. Windows Phone application server module.

The following is a general description of activities within the GDS:

-   -   1. LDS host-side server.        -   a. Manage connections to remote LDS units.        -   b. Upload/download sensor even records, as requested by the            remote LDSs.        -   c. Store/retrieve these records using the resident database            engine (mySQL, etc.).        -   d. Generates requested analytics from the local database.        -   e. Cache all requested analytics. These will be used by the            web-server and app-server delivery subsystems.        -   f. Manage user and subscriber authentication as requested by            the remote LDSs.        -   g. Interface with the subscriber billing and account            management system.    -   2. The resident web-server will serve analytics to        internet-connected subscribers that are accessing the system        using a web-browser.    -   3. The resident iOS app-server will serve analytics to        internet-connected subscribers that are accessing the system        using an iOS device.    -   4. The resident Android app-server will serve analytics to        internet-connected subscribers that are accessing the system        using an Android device.    -   5. The resident Windows Phone app-server will serve analytics to        internet-connected subscribers that are accessing the system        using a Windows Phone device.

There are many possible ways of analyzing sensor-data, from real-timeevents (at a football game), to more generalized statistical research.

A variation of one embodiment of the present invention is illustrated inFIG. 9 wherein the sensor module 10′ has an antenna within the housingthereof such that an arcuate space for the antenna in the headband isnot required. Additionally, arrow indicia is displayed on the outersurface of the headband at the pocket receiving the sensor module 10′ toassure that the individual wearing the headband has vertically properlyaligned the headband and the accompanying sensor module. Additionally,portions of non-Newtonian fluid are positioned on the inner surface ofthe headband to separate the skull from the sensor module. Thenon-Newtonian fluid, in one example, will be supplied in four smallovals sewn into the inner lining of the headband SIM pocket. Thenon-Newtonian fluid serves as a small buffer against the SIM and theback of the head which will allow the SIM to generate a more accurateimpact reading.

From the above, it should be appreciated that certain aspects of thepresent invention permits continuous sampling and recording of high-gaccelerometer and gyro data since, when an impact/event is detected, thedata that was recorded at the impact point is transmitted along withdata relating to what happened before the impact. More particularly,high-g accelerometer (linear) and gyroscope (rotation) aresampled/monitored at, for example, a 1 KHz rate and successive samplesof the linear and rotational sensor data are placed in a circularbuffer. One system consistent with principles of the present inventioncan be used in conjunction with specialized software to perform acognitive and balance evaluation test when data indicates that suchtests are desirable.

The above described embodiments of the present invention can be variedas will be understood by one of ordinary skill in the art, for example,use of different radio frequencies and radio transmission chips andcircuits for data transmission, inclusion of additional sensors andsensing capabilities within the sensor module, use of alternative powersources permitting charging mechanisms such as induction charging, andmotion-based energy “harvesting”. Additionally, the present inventioncan utilize cell phones, tablet computers, laptop computers or othersimilar devices as an alternative to a dedicated LDS system for exampleusing Bluetooth or WiFi for communication with the sensor modules, theuse of a self-contained LDS system including integral computingcapability but not including an external laptop computer device, asystem using a “self-contained” LDS incorporating some elements offunctionality from the GDS to allow use without a GDS system.Alternative designs could also utilize a general purpose networktechnology (rather than one specifically deployed for the application ofthe present invention within an LDS) examples of which would be a WiFinetwork, cellular phone or paging network and a general purpose datacommunications network such that alternative designs could include asystem without and LDS but where some of the functionality of the LDS ismoved to the GDS to allow correlation with the axes in the sensormodule.

There are many issues with determining whether an event has occurred insensing whether an individual has incurred a concussive force. Variousadditional embodiments described herein address some of these issueswithin a sensor and associated systems for analyzing, tracking and/orreporting sensed forces, and for providing better sensors, systems andmethods for determining such forces. For instance, one issue withexisting sensors is that wearable acceleration sensors worn external tothe body are susceptible to false events from direct contact with thesensor. Filters based on frequency analysis, heuristics, and machinelearning are only a partial solution, and additional improvements areneeded. According to one aspect of the present invention, multiple3-axis sensors are provided that are spaced around the head with aflexible headband. It is appreciated that with such a system, a highdegree of correlation between the sensors indicates it was the head thatmoved, and not just the sensor.

It is also appreciated that there are problems with wearableacceleration sensors in that they are susceptible to significant noisewhen measuring rotation, rendering rotation measurements highlyinaccurate. A primary cause for this is “waves” in soft tissues of theperson's body located under the sensor causes oscillating rotation.Accurate rotation measurements are not only required to determinerotation forces on the brain, but also to translate the linearacceleration measured at the sensor to a measurement of forces at thecenter of the head.

According to one aspect, it is appreciated that such oscillations may beeliminated by spacing three (3) or more accelerometers around the headand looking at differential linear accelerations to determine rotationalacceleration. This effectively spreads the measurement out across thespan of the sensors, eliminating the noise susceptibility of measuringat a single point. In particular, waves have a significantly reducedeffect when measuring across multiple points spanning the head asopposed to measuring at a single point. In a single-point measurement,the waves create “wobble” in the sensor, which is only limited by therelatively small footprint of the sensor. By distributing sensors aroundthe head, a much larger “virtual footprint” may be created for thesensor, which averages out the small localized effects of waves in theskin.

FIG. 10 shows an example configuration of a sensor (side view) andheadband arrangement 1000 according to one embodiment. As shown in FIG.10, multiple three (3)-axis accelerometers (e.g., accelerometer 1004)are used and located within the headband to more accurately detectforces applied to the head. Optionally, the sensors are not all locatedwithin the same plane such that component forces in different directionscan be more accurately sensed. As shown in FIG. 10, the main electronics1003 may be located in a portion of the headband located at the back ofthe head, and additional 3-axis accelerometers are located on each sideof the headband, located behind the ears of the wearer (e.g., wearer1005). The headband may include a portion that is flexible butnon-elastic (e.g., portion 1002), and the portion may include a flexibleprinted circuit board (PCB). The headband may also include an elasticportion (e.g., portion 1001) that holds the flexible portion to the headof the wearer.

FIG. 11 shows a top view of the location of sensors within the headband.As shown, the headband may be worn by a wearer 1100, and the headbandmay include sensors located near the back of the ears (e.g.,accelerometers 1101A, 1101B). Also, the main electronics (e.g., element1102) may include an additional accelerometer, a gyro, microcontroller,battery, among other elements.

As discussed above, there may be additional computations that may berequired when using multiple 3-axis sensors. More particularly, it maybe desired to determine the rotational acceleration on the head, as itis appreciated that damaging forces to the head are correlated withrotational acceleration. The following is an example calculation:

Rotational Acceleration Computation

-   The following points are defined in 3-dimensional space:

L—location of the left accelerometer

R—location of the right accelerometer

B—location of the back accelerometer

C—the midpoint between L and R

Also defined is a coordinate system where all accelerometers lie in thex-y plane, the x-axis runs through B, the y axis runs through L and R,and the z axis points up (e.g., as shown in FIGS. 12 and 13).

We can then compute the rotational acceleration about each of the three(3) axes using the following equations:

$a_{C} = \frac{a_{L} + a_{R}}{2}$$\alpha_{x} = {\frac{a_{zR} - a_{zL}}{\overset{\rightarrow}{RL}} - {\omega_{y}\omega_{z}}}$$\alpha_{y} = {\frac{a_{zB} - a_{zC}}{\overset{\rightarrow}{BC}} - {\omega_{x}\omega_{z}}}$$\alpha_{z} = {\frac{a_{xR} - a_{xL}}{2{\overset{\rightarrow}{RL}}} - \frac{a_{yB} - a_{yC}}{2{\overset{\rightarrow}{BC}}}}$

Where:

-   -   aL, aR, and aC are the linear accelerations at L, R, and C        respectively    -   α is the rotational acceleration    -   ω is the rotational velocity

Multiple Accelerometer Data Processing Flow

Below is described an example process for processing data from multipleaccelerometers:

-   -   1) An event is triggered by all three accelerometers reading        above a threshold (typically, for example, 16G for athletics).    -   2) The event data comprises accelerometer samples for a period        of time pre-trigger and post-trigger. For athletics, this is        approximately 10 milliseconds of pre-trigger data and 50        milliseconds of post-trigger data.    -   3) The 3-axis data from the Left and Right accelerometers is        transformed into the coordinate system of the Back        accelerometer. The typical arrangement will have the Left and        Right accelerometers rotated about the Z-axis relative to the        Back accelerometer. In this case, the transformed acceleration        samples will be computed by first creating a rotation matrix for        each sensor as follows:

${R_{z}(\theta)} = \begin{bmatrix}{\cos \; \theta} & {{- \sin}\; \theta} & 0 \\{\sin \; \theta} & {\cos \; \theta} & 0 \\0 & 0 & 1\end{bmatrix}$

Where θ is the angle of rotation about the Z-Axis.

-   -   Each acceleration data point is then multiplied by this matrix        to compute the transformed data in the common coordinate system.    -   4) The acceleration data from each accelerometer can be compared        using a correlation function (such as the Pearson product-moment        correlation coefficient). If the three measurements have high        correlation (above some specified threshold) then the hit can be        considered valid. According to one implementation, if 2 out of 3        of the measurements are highly correlated, then the event is        processed with those 2 measurements, with the non-correlated        measurement discarded. This corresponds to the case where one of        the sensors was directly contacted during a real head impact. It        should be noted that processing an event with only 2 sensor        measurements may result in degraded accuracy, particularly in        the rotational acceleration calculation.

It should be appreciated, however, that any number of accelerometers maybe used to increase the accuracy of the sensor.

There also exists a problem of how to build a headband with multipleaccelerometers. For instance, it is appreciated that it would bedesirable to have a headband that includes multiple accelerometers thathave non-rigid mechanical coupling to each other through the headbandsuch that they achieve mechanical coupling via the wearer's head. Inthis way, the multiple accelerometers have a higher chance of detectingan applied head force rather than a force applied to one of the otheraccelerometers or from the headband.

One embodiment of the present invention relates to a rigid-flex circuitwith rigid portions to hold accelerometers and other circuit componentsat the back of the head and approximately above each ear, with flexibleportions connecting them. The circuit may be bonded to a fabric backingand/or encapsulated in a flexible plastic housing for strength,durability, and protection from sweat and the elements. FIG. 14 shows anexample layout of such a rigid-flex circuit within a headband.

In particular, FIG. 14 shows an example headband/sensor arrangement 1400including a number of rigid PCB elements connected by flexible PCBsections. In particular, a rigid PCB section 1401 is coupled to a rigidPCB 1409 that houses main processing components through a flexible PCBsection 1404. The rigid PCB section 1409 may house the battery, amicrocontroller 1405, a gyro/low-G accelerometer 1407, a three-axisaccelerometer (e.g., accelerometer 1408), capacitive sensor (e.g.,capacitive sensor chip 1415), and battery 1406, among other components.In one embodiment, antennas (e.g., antenna 1402) is embedded within aflexible PCB portion. In another embodiment, a capacitive sensor pad(e.g., capacitive sensing pad 1414) is positioned within the flexiblePCB portion (e.g., flex PCB 1410). Flexible PCB portions may alsoinclude one or more connections to one or more components (e.g., viapower and data connection 1413). Another rigid PCB section (section1411) may include a third three-axis accelerometer 1412.

According to another embodiment, accelerometers 1403, 1412 arepositioned accurately within a defined plane because they are positionedwithin the flexible/rigid PCB component which is held to the wearer'shead (e.g., via an optional headband). Rigid flex printed circuit boardsare boards that may use a combination of flexible and rigid boardtechnologies in an application. Most rigid flex boards comprise multiplelayers of flexible circuit substrates attached to one or more rigidboards externally and/or internally, depending upon the design of theapplication.

The flex portion of the assembly may be manufactured, for example, on aflexible base material, such as polyamide film. Metal layers areattached to the base layer to create the conductive layers, either byapplying metal foil with an adhesive or electroplating or other method.Multi-layer flex circuits may be created, for example, by laminatingmultiple layers together. However, it should be appreciated that otherflexible materials, shapes of the sensor and elements, and solutions maybe used (e.g., flexible conductive fabric), and that certain aspects ofthe invention are not limited thereto.

Described below is an example process of making a measurement, and howis noise eliminated or reduced.

-   -   First, the linear acceleration at each of the 3 sensors is        measured for the duration of the event.    -   Next, the rotational velocity and acceleration of the head is        computed at each discrete time step during the event. (see        below).    -   Finally, the acceleration at the head's center of mass is        computed using the linear acceleration measurements and the        computed rotational acceleration and rotational velocity using        the following equation:

a _(C) =a _(S)+ω×(ω×{right arrow over (CS)})+α×{right arrow over (CS)}

-   -   Where    -   a_(C) is the accleration at the Center-of-Mass    -   a_(S) is the acceleration at the sensor    -   ω is the rotational velocity    -   α is the rotational acceleration    -   CS is the vector from the sensor to the center-of-mass

Equations to determine rotational acceleration from linear accelerationat multiple points (e.g., the equations for computing rotationalacceleration about each of the three (3) axes as discussed above)requires one of the following:

-   -   a) measurements at a minimum of 4 non-coplanar points    -   b) knowledge of the rotational velocity during measurement

However, it is appreciated that a 4 non-coplanar point sensorarrangement solution is generally not practical (e.g., a sensor locatedon top of the head or under the chin may be required), and thusknowledge of rotational velocity may be needed. One solution to this isthat all points in a headband are roughly coplanar (e.g., as provided bythe rigid/flex PCB arrangement), so to have knowledge of the rotationalvelocity, one implementation may use a MEMS Gyro sensor. This sensor mayencounter noise during an impact event, however it can be used todetermine the starting and/or ending conditions. The rotational velocityduring the event can be determined by integrating the rotationalacceleration derived from linear acceleration measurements, and applyingthis to either the starting or ending conditions measured by the gyro,as discussed above. Events may be triggered, for example, from linearaccelerations exceeding a defined threshold.

Also, as discussed, the starting conditions may be determined using thegyro, and then the linear accelerometer data may be used to determinerotational velocity. In particular, given a rotational velocity startingcondition, the equations above can compute the rotational acceleration.This rotational acceleration can then be used in a discrete timeintegration to determine the rotational velocity at the next sampletime. This process is then repeated to compute rotational velocities andaccelerations for the entire event duration. This process is symmetric,so the same computations can be done working backward from a measurementat the end of the event as described in detail below.

One issue relating to the use of a MEMS gyro includes the issue thatMEMS gyros are power-hungry components (relative to other components inthe headband) and therefore the use of the MEMS gyro reduces batterylife significantly. One solution to this issue includes keeping the gyropowered down until a high-G event is detected. At this point, the systempowers on the gyro and starts taking measurements. Mostcommercially-available MEMS gyros take 30-100 milliseconds to startproducing valid data after power on. It is appreciated that when a validrotational velocity measurement from the gyro is achieved, it ispossible to work backward from this point iteratively using differentialmeasurements from the linear accelerometers to determine the history ofrotational velocity and rotational acceleration during the impact event.

The high-G event may be initially detected as described above, using theaccelerometers. For instance, the high-G event may be defined as anyevent where all three accelerometers measure an acceleration above somespecified threshold. The severity of the event may be detected usingmetrics such as Peak Linear Acceleration (PLA) and Peak RotationalAcceleration (PRA). Other metrics could be envisioned that take intoconsideration the duration or total energy of the event.

Below is a description of the example calculations that can be used totrace back the event:

-   -   This is a discrete-time integration in reverse, which can be        approximated using the following function:

ω_(t−1)=ω_(t)−α_(t) Δt

-   -   where:    -   ω_(t−1) is the rotational velocity at step t−1    -   ω_(t) is the rotational velocity at step t    -   α_(t) is the rotational acceleration at step t    -   Δt is the time interval of each step

Another issue with sensor operation is that it would be beneficial toknow whether a headband (or any other type of body sensor device) isbeing worn at a given time, both to turn the device off when not in use,as well as to filter events that may occur during transport and storage.It is appreciated that an additional sensor may be used to determinewhether the device is being worn by a user. For example, in oneimplementation, a low-power capacitive proximity sensor can be usedwhich can detect changes in electric field when an object is placed nextto the sensor area. Furthermore, a sensor which can measure electricalpermittivity can discriminate between placement next to the body andplacement next to other objects, such as a table.

The sensor may be located, for example, as shown above within theheadband. It may include a capacitive sense pad embedded within one ofthe PCB elements of the headband. In particular, the sensor pad etchedmay be into the conductive layers of the PCB. This pad may be connectedto a capacitive sensing chip, which controls and monitors the state ofthe sensor pad. This chip interfaces with the microcontroller via acommunications bus (I2C or SPI) and/or via general-purpose I/O signals.

Be implementing a proximity sensor along with the overall sensor device,it is appreciated that the system is now able to treat any event whilethe device is not being worn as a false event. Second, the system canuse the proximity sensor for power management, powering down theheadband when not worn, and powering the headband up automatically whenthe headband is placed on the head. In this way, battery life isextended.

It is appreciated that there are additional issues with using antennaswithin a headband or other type of worn device. In particular, it isappreciated that both the antenna used for connecting the headband tothe network and the capacitive proximity sensor require relatively largeantennas for optimal operation. Antennas extending from the mechanicalpackage of the headband are prone to breakage. To protect these devices,one implementation may include embedding both the antenna (900 MHz or2.4 GHz) and capacitive sensor in the flex circuit that connects therigid portions of the headband. An example implementation is shown inFIG. 14.

The phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. Any references toembodiments or elements or acts of the systems and methods hereinreferred to in the singular may also embrace embodiments including aplurality of these elements, and any references in plural to anyembodiment or element or act herein may also embrace embodimentsincluding only a single element. References in the singular or pluralform are not intended to limit the presently disclosed systems ormethods, their components, acts, or elements. The use herein of“including,” “comprising,” “having,” “containing,” “involving,” andvariations thereof is meant to encompass the items listed thereafter andequivalents thereof as well as additional items. References to “or” maybe construed as inclusive so that any terms described using “or” mayindicate any of a single, more than one, and all of the described terms.Any references to front and back, left and right, top and bottom, upperand lower, and vertical and horizontal are intended for convenience ofdescription, not to limit the present systems and methods or theircomponents to any one positional or spatial orientation.

Having thus described several aspects of at least one embodiment of thisinvention, it is to be appreciated that various alterations,modifications, and improvements will readily occur to those skilled inthe art. Such alterations, modifications, and improvements are intendedto be part of this disclosure, and are intended to be within the spiritand scope of the invention. Accordingly, the foregoing description anddrawings are by way of example only.

What is claimed is:
 1. A sensor comprising: a flexible housingcomprising a plurality of 3-axis accelerometers, the flexible housingbeing adapted to be worn by a user and being in contact with a body partof the user; and a module coupled to the accelerometers including aprocessor which is adapted to sense forces experienced by the body part.2. The sensor device according to claim 1, wherein the sensor isconstructed within a headband.
 3. The sensor device according to claim1, wherein the flexible housing comprises at least three 3-axisaccelerometers, and wherein the housing comprises flexible couplingsbetween the at least three 3-axis accelerometers.
 4. The sensor deviceaccording to claim 3, further comprising flexible circuits that couplethe module to two of the at least three 3-axis accelerometers.
 5. Thesensor device according to claim 1, wherein at least one of the 3-axisaccelerometers is positioned at the back of the head of the user inalignment with the median nuchal line.
 6. The sensor according to claim1, wherein the module is adapted to determine rotational accelerationfrom multiple measurements of linear acceleration.
 7. The sensoraccording to claim 6, wherein the module is adapted to receive at leastthree measurements of linear acceleration from non-colinear pointswithin the sensor.
 8. The sensor according to claim 6, furthercomprising a sensor adapted to measure rotational velocity.
 9. Thesensor according to claim 8, wherein the sensor is adapted to measurerotational velocity includes a MEMS gyro.
 10. The sensor according toclaim 9, wherein the module is adapted to power on the MEMS gyroresponsive to a detection of an event.
 11. The sensor according to claim10, wherein the event includes a measurement of an acceleration above apredefined threshold.
 12. The sensor according to claim 1, furthercomprising a proximity sensor adapted to detect whether the sensor is incontact with the body part of the user.
 13. The sensor according toclaim 12, wherein the module is adapted to power on the sensorresponsive to detection by the proximity sensor indicates that sensor isbeing worn by the user.
 14. The sensor according to claim 12, whereinthe proximity sensor includes a capacitive sensor pad.
 15. The sensoraccording to claim 1, wherein the housing includes a plurality of rigidcircuits associated with each of the plurality of 3-axis accelerometers.16. The sensor according to claim 15, wherein the plurality of rigidcircuits are coupled by a plurality of flexible circuits.
 17. The sensoraccording to claim 1, further comprising, within the flexible housing,at least one antenna adapted to communicate with one or more externalsystems.
 18. The sensor according to claim 1, further comprising, withinthe flexible housing, a capacitive sensor pad adapted to detectproximity of the sensor to the body part of the user.
 19. The sensoraccording to claim 1, wherein at least one of the plurality of 3-axisaccelerometers is coupled to a rigid circuit associated with the module,the at least one accelerometer being coupled to the rigid circuit by aflexible circuit.